The nationat litmoqraphina compaf



UNITED STATES PATENT FFICE.

JOHN ZIMMERMAN AND JOHN K. UNDERDOWN, OF CHICAGO, ILLINOIS, ASSIGNORS TO THE NATIONAL KEY-OPENING CAN COMPANY,'OF

SAME PLACE.

SHEET-METAL VESSEL.

SPECIFICATION forming part of Letters Patent No. 515,103, dated February 20, 1894.

Application filed May 23,1893.

To all whom it may concern.-

Be it known that we, JOHN ZIMMERMAN and JOHN K. UNDERDOWN, of Ohicago,in the county of Cook and State of Illinois,have invented certain new and useful Improvements in Sheet-Metal Vessels; and we do hereby declare that the following is a full, clear, and eX- act description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a partof this specification.

This invention has reference to weakened lines in the sheets of metal of which cans are made, said lines being provided for the purpose of allowing a strip or part of the can to be detached so as to give access to its contents. Usually thedetachable portions of the cans are in the form of strips forming part of the can bodies and while, so far as our invention is concerned, it is immaterial in what part of the can the detachable strip or portion is situated, we will describe it as being in the body sheet and extending circumferentially thereof. The `weakened line herein described is of that well known kind which is formed by thinning the metal under compression, as. for example, between rollers or otherwise, as distinguished from thinningI the metal by an incision or gash. The weakened line of this invention also has the familiar characteristic of being formed along the apex of a grooverib, as for example, illustrated in Letters Patent of the United States, Nos/186,522 and 486,523, granted to John Zimmerman, one of the present inventors, November 22, 1892.

A primary object had in view in this invention is the provision of a weakened line along which the rupture will more certainly follow than in other constructions and particularly from which the rupture, if it shall ever depart, will not run into or across the detachable strip and thus deprive the can of the means for further opening it.

To this end the invention contemplates a particular formation of a rib and its attendant groove, the leading feature of which is abruptness of that wall of the groove adjacent to the detachable strip, or, in other words, proximate perpendicularity of that wall of the rib to the surface from which it rises, the

Serial No. 475.270. (N0 model.)

opposite wall being less abrupt or more inclined to said surface.

In the accompanying drawings we not only show a piece of sheet metal provided with the groove-rib having a weakened line,in accordance with our invention, but to make said invention more plain, we also illustrate means by which such a weakened line or lines may be, and preferably are, produced.

In the drawings, Figure 1 represents roller ribbing and grooving dies arranged opposite each other, the ribbed entering die being shown in section, and the dies being adapted to make two weakened lines and to therefore afford an intermediate detachable strip. Fig. 2 is an enlarged view of proximating portions of the roller dies, in side elevation, the enlargement being for the purpose of more dis tinctly illustrating the relative forms of the ribs and grooves of said dies. Fig. 3 illustrates a piece of sheet metal after having been passed between the rollers of Fig. 2, said sheet of metal being shown in section transverse to the ribs and grooves and illustrating the relative thicknesses of different parts of the deiiected portions of the metal. Fig. 4. shows a section of a sheet across a weakened line, still further enlarged.

E represents the grooved roller die and F the ribbed roller die. The grooved die E has one or more V-shaped, circumferential grooves e each having its opposite walls or faces e and e2 unequally abrupt or inclined -with respect to a plane at right angles to the die axis, substantially as shown, and desirably separated by a cylindric or slightly concaved surface e8 at the bottom of the groove, as more distinctly shown in Fig. 2. The die F has ribs f f arranged t-o enter the grooves e e and formed to present a more acute angle than that formed by the sides of the several grooves in the opposing die and so as to exhibit, when inserted into said grooves and viewed against a light, tapering or wedgeshaped spaces between their several side faces and those of the grooves, as also more plainly indicated in Fig. 2. The ribsf project from the cylindric body of the die F a distance greater than the depth of the grooves so that, when the opposing rollers bear upon IOO the opposite surfaces of an interposed sheet, the metal of said sheet will be thinned by compression at the bottom of the groove-ribV formed thereby. Preferably the side faces of the ribs ff which are adjacent to the more abrupt walls e2 Of the grooves, are in planes which are at or proximately at right angles to the axis of the roller, and the apices of the ribs are quite thin and preferably yas thin or sharp as practicable consistent with smoothness and solidity and said thin edges of the ribs are arranged nearly or quite Opposite those sides of the narrow bottoms e3 of the grooves which are adjacent to the more abrupt walls e201` the latter. Vhen the dies are thus constructed and arranged and are suitably adjusted, and when a blank (indicated by dotted lines, at G in Fig. l and in full lines in Fig. 3) is passed between said dies, the edges of the ribs f produce a stretching action upon the metal embraced between the more abrupt faces of the ribs and grooves, which actionl is calculated to draw out and thin down said metal on the corresponding sides of the resulting ribs in the metal, as in dicated at g g in Figs. 3 and 4, as well as to thin the metal by direct compression at the apices of the ribs or bottoms of the grooves,

as also shown in Figs. 3 and 4.

It will be understood that the metal sheet may be given either one Or two weakened lines for the. purpose of affording a detachable strip G. If only one such line be employed, it will be parallel with the edge of the sheet and near enough to it to give a detachable strip between said weakened line andv the sheets edge, and if two such lines be employed they will be parallel with each other and near enough together, as shown in the drawings, to afford a detachable strip between them.

When two weakened lines are to be formed in a sheet it has been found desirable to arrange the more abrupt sides of the ribs and grooves adjacent to each other and, when but one such line is to be formed, to arrange' said more abrupt face adjacent to the edge of the can body or blank, so that the thinned side or sides of the rib or ribs will belong to the detachable strip.

The construction of the weakened line in the blank or metal sheet as above described, namely, by placing it along the apex of a ribgroove one side or wall of whichis perpendicular or proximately perpendicular tO the plane of the sheet at the opposite side of which has a greater inclination thereto, the more abrupt wall being thinned from the base to the apex of the rib-groove is found to insure a continuity of the metal coating upon the sheet and at the same time the strip is found to tear with far greater certainty along the weakened line than in any other construcrib, even if the key upon which the strip isv wrapped in detaching it be held very much inclined from a right angle to the direction of the strip, and it is particularly free from a tendency to tear down the abrupt and practically vertical side of the rib and into and across the strip, so that there is practically no liability of the strip to become severed or torn off and detached before the can is fully4 Opened.

We claim as our invention- 1. A metal sheet for a keyopening can or other vessel having a compressed weakened line, concerned in giving detaehability to a part of the vessel, said weakened line being along the apex of a groove-rib the Walls of which are unequally abrupt and the more labrupt of which walls is adjacent to the detachable part'or strip.

2. A metal sheet for a key-opening can or other vessel having a compressed weakened line along the apex of a groove-rib, the walls of said groove-rib being unequally abrupt and the more abrupt wall thereof being of decreasing thickness in a direction from the base to the apex of the rib.

3. A metal sheet for a key-opening can or other vessel having two compressed weakened lines along the apices of parallel groove-ribs between which is situateda detachable strip, the walls of each of said ribs being unequally abrupt and having their more abrupt sides directed toward the intervening detachable strip. 4. A metal sheet for a key-opening can or other vessel having two compressed weakened lines along parallel ribs between which is situated a detachable strip, the walls of each of said ribs being unequally abrupt and having their more abrupt sides directed toward the intervening detachable strip, the metal in said more abrupt sides or walls of the ribs being of decreasing thickness in a direction from the bases to the apices of the ribs and the metal at the apices being thinner than the body of the sheet. A

ln testimony that we claim the foregoing as our invention we affix our signatures in presence of two witnesses.

JOI-IN ZIMMERMAN.

s JOHN K. UNDERDOWN. Witnesses:

M. E. DAYTON,

C. CLARENCE POOLE.

IIO 

